Isohaemagglutinin synthesis starts 2-4 months after birth, growing progressively and reaching adult values at the age of 5-10 years. Isohaemagglutinin concentration decreases with age. Isohaemagglutinins are mostly immunoglobulins belonging to the class IgM, but also IgA and IgG. Agglutination titter shows correlation with the total concentration of those three immunoglobulin isotypes. For the time being there are few data on the isohaemagglutinin titter level in various diseases. Purpose of this work is to determine whether there are any isohaemagglutinin titter alterations in patients with neoplasia. Isohaemagglutinin titter was investigated in 177 patients treated at the Institute of Oncology and Radiology and 340 blood donors. Out of 177 patients, 31 had Hodgkin's lymphoma (HL), 89 had non-Hodgkin Lymphoma (NHL) and 57 had metastatic solid tumors (MST). Statistical evaluation included Kruskal-Wallis and Mann-Whitney tests. In all groups of patients isohaemagglutinin titters were considerably lower as compared with the healthy population (p<1 ´ 10e-5). There was a significant difference in titter values (p=0.003) between O blood group patients with NHL where anti-A1 titter was significantly lower (Med=8; range: 1-256) compared with anti-A1 titter in patients with O blood group suffering from MST (Med=16; range: 2-64). Anti-B titter in the same groups of patients also showed lower values (p=0.042); in NHL anti-B titter values was Med=4, range: 1-32 vs Med=8, range: 1-64 in MST. In the group of patients with HL, A blood group was far more frequent (17/31) compared with the group with MST (22/57) (p=0.02). Pretherapy determination of isohaemagglutinin titter in patients with malignant diseases shows that it is significantly lower than the titter in healthy population. Abnormally low isohaemagglutinin titter value irrespective of the type and site of the malignant tumor, points to insufficiency of the IgM-related humoral immune response, to malignancy as a systemic disease, and places isohaemagglutinins among biological markers.

Keywords: metastatic solid tumors, malignant lymphoma, Isohaemagglutinins